(a) Field of the Invention
The present invention relates to an apparatus for controlling the transport of a magnetic tape in a tape recorder, a video tape recorder and like devices, which is arranged so that a braking force is applied to the reel stands only for a predetermined period of time upon generation of a stop command signal, to bring the running magnetic tape to a halt.
(b) Description of the Prior Art
In conventional tape recorders, the transport of a magnetic tape, i.e. normal play, fast forward feed and rewind, is brought to a halt not only by shutting off the driving of the reel stands, but also by application of a braking force to the reel stands on both the feed side and the take-up side through a braking mechanism to quickly stop the rotation of these reel stands, to prevent an extra travel of the tape due to its inertia of movement.
Among the conventional braking mechanisms of the so-called electromagnetic drive type designed for driving the mechanism by solenoid means, there are the following two types. One of them is arranged so that the mechanism is normally held in the state that a braking force is being applied to the mechanism by spring means, and this braking action is prevented only when an electric power is supplied to the solenoid means. The other type is opposite to the above-mentioned manner of operation. That is, mechanism is normally held, by spring means, in the state of being released of braking force, and it is only when an electric power is supplied to the solenoid means that a braking force is applied to the mechanism.
In the first-mentioned type of braking mechanism, electric power has to be applied continuously to the solenoid means throughout the period of transport of the magnetic tape. On the other hand, the latter type of braking mechanism requires that electric power be supplied continuously to the solenoid means throughout the period of rest of the magnetic tape. In each of these two types of braking mechanisms, therefore, it will be appreciated that, in the ordinary manner of use of the tape recorder, electric power has to be supplied to the solenoid means continuously for an extended period of time, and thus there has been the drawback that the consumption of power supply is considerably large.
Also, in the conventional ordinary tape recorders, in either the fast-feed mode or rewinding mode wherein the tape is forced to run at a high speed by rotating the shafts of the reel stands at a high speed, if the user wants to instantaneously switch this mode over to either the playback mode or the recording mode wherein the magnetic tape is caused to run at a constant normal speed between a pinch roller and a capstan, the tape is subjected, at the very time of the switching, to a large tension in that portion of the tape locating between the take-up side and the pinch roller side, and as a result there is the fear that the tape is elongated or cut apart. For this reason, the above-mentioned conventional tape recorders having a high potential of such fears as described above, there is provided a mechanical interlocking means in the operating mechanism of the tape recorder, to insure that, when the recorder is in its fast-feed mode or rewind mode, the reproduction button cannot be actuated unless after the stop button is depressed. In those tape recorders which are not provided with such interlocking means as mentioned above, instruction notes are usually provided for the user to practice so as not to depress the reproduction button abruptly when the machine is in its fast-feed mode or rewind mode, and to depress the stop button before depressing these operating buttons.
Anyway, the conventional operation pattern which requires the user to first perform an operation to bring the running tape to a halt when the user wants to changeover from the fast-feed mode or the rewind mode to either the playback mode or the recording mode, and then to perform a further operation to start either the playback or the recording, cannot be termed as being convenient in its operability.